/Engine/Plugins/FX/Niagara/Source/Niagara/Classes/NiagaraParameterCollection.h
Takes the real parameter name used under the hood and converts to the friendly name for use in the UI. Converts from "CollectionUniqueName_ParameterName" to "ParameterName".
[FNiagaraVariable](API\Plugins\Niagara\FNiagaraVariable) CollectionParameterFromFriendlyParameter ( const [FNiagaraVariable](API\Plugins\Niagara\FNiagaraVariable) & FriendlyParameter ) const